What keeps you up at night?

I travel alot for work and a good bed can be the difference between a good nights sleep or tossing and turning all night. If I have to get up early for a trip I'm excited about, I'm like the kid waiting for Christmas morning. I can't sleep because I'm riddled with excitement!

What keeps you up at night? Work? Relationships? Food? Alcohol? Drugs? Having to Piss? Horniness?

like you guys say thinking mainly, also studying, making music and my bed/sofa. It will be the end of me. Hah luckily I don't have the internet at home otherwise i'd say the internet (realjock included).